In the present state of the art it is customary that each system designed to detect data information within a selectable field of view be provided with its own separate pointing apparatus as well as a discretely associated display means. This is generally true where spectrally distinct regions of the electromagnetic spectrum emanating from a common field of view may be sensed by different equipment systems. For example, a sensor such as a television camera may customarily be operatively employed with a discrete display monitor cathode ray tube for shipboard television systems which detect and display radiation within the visible region of the electromagnetic spectrum; there also may be separate sensors and display means in discrete equipment systems associated with other portions of the electromagnetic spectrum such as the near infrared, middle infrared, and far infrared. In addition to such passive systems, there may also be active systems, such as radar and sonar systems, which are separately operative to produce radar and sonar displays, respectively, though their surveillance may be directed to the same field of view as one or more other systems.
Such a plurality of discrete systems and multiplicity of separate displays, each associated with a different sensor, result in inefficiency and a lack of coordination of the signal information received. In such separate systems and display of signal information, one operator is confined to each display for continuous monitoring of the signal information presented. Thus, the present state of the art, not only results in inefficient usage of trained manpower, but also gives rise to a lack of precise field of view commonality between the plurality of spectrally distinct regions of the electromagnetic spectrum which may contain useful signal information; as a consequence there is a concomitant lack of registration of the several spectrally distinct regions of information which may be provided by a common field of view.
Moreover, in the present state of the art the several equipment systems which may be employed to develop signal information within spectrally distinct regions of the electromagnetic spectrum, each employs a separate, individually associated system pointing equipment. This results in an unnecessary complexity of multiple servomechanism controlled pointing systems which are very difficult to synchronize in operation to insure a precise common field of view such as would enable the coordinated interpretation of spectrally distinct regions of signal information emanating from a common field of view.
For example, it is common practice in the present state of the art to employ one servomechanism controlled system having a one or two axis gimbal which positions a television camera to sense electromagnetic radiation within the visible region, while additional separate servomechanism systems are operated separately under discrete control for imaging electromagnetic energy within several other spectrally distinct infrared regions.
Moreover, it is known that the same field of view will present detectable amounts of energy within spectrally distinct regions of the electromagnetic spectrum depending upon the prevailing conditions such as, for example, whether it is viewed under daytime or nightime conditions. Further, the spectrally distinct detectable amounts of energy within the same field of view will differ in accordance with the prevailing weather conditions, such as, for example, whether there is clear visibility or fog conditions, or rain conditions prevail. Thus, each of the two contrasting conditions of day and night may develop a multiplicity of compounded conditions such as clear weather, fog, or rain.
Within each or several of these various compounded conditions it is known that certain distinct spectral regions of the electromagnetic spectrum are markedly more penetrative and therefore particular spectral regions are more useful in detecting the presence of targets, for example, within a selected field of view in accordance with the prevailing weather conditions and also whether it is a daytime or a nightime operation.
Accordingly, it is highly desirable that a system be provided for developing a plurality of selected spectral ranges of energy received from a common field of view to provide maximum resolution and coordination of signal information under all weather conditions.